WO1992012341A1

WO1992012341A1 - Pressure accumulation type fuel jetting device

Info

Publication number: WO1992012341A1
Application number: PCT/JP1992/000017
Authority: WO
Inventors: Yasuhiro Kariya; Takashi Iwanaga; Kenji Magario; Takayoshi Kawaguchi; Nobuhiko Shima; Mitsuru Ban
Original assignee: Nippondenso Co., Ltd.
Priority date: 1991-01-14
Filing date: 1992-01-13
Publication date: 1992-07-23
Also published as: EP0531533B1; EP0531533A4; EP0531533A1; US5511528A; DE69218326D1; DE69218326T2

Abstract

Reliability of a system, in which fuel pressurized by a high pressure supply pump is accumulated in a common rail, is affected a great deal when piping connected to the common rail is broken or pulsation of fuel injection occurs, because of high pressure of the fuel. This invention is to improve reliability of the system by incorporating a mechanism to prevent outflow of fuel from the common rail even when the piping is broken or a mechanism to attenuate the pulsation of pressurized fuel into pipings around the common rail.

Description

Specification

Accumulator type fuel injection device s Technical field

The present invention relates to an accumulator type fuel injection device used for a diesel engine or the like. Background art

Conventionally, as shown in, for example, Japanese Patent Application Laid-Open No. 59-16858-58, as one of the fuel injection devices for diesel engines, there is a pressure-accumulation type fuel injection device. A high-pressure fuel from a high-pressure pump is stored in a type of surge tank called a surge tank, and this is injected and supplied to the engine by opening an injection valve. In Japanese Patent Publication No. 9 3656, a safety device S is provided for the injection valve, and the fuel passage is closed when a predetermined amount or more of fuel is supplied to the injection valve due to damage to the injection valve.

However, since the fuel pressurized to a very high pressure (for example, 150 MPa) by the cam mechanism of the high-pressure supply pump is stored in such a pressure accumulation pipe called a common rail, the pressure from the low-pressure supply pump is high. There is a possibility that the high-pressure flow path up to the injection valve via the common rail will be damaged and the high-pressure fuel will spill outside, or the reflected wave generated by the injection valve of one cylinder will be transmitted to the other via the common rail. This has the problem that it is likely to be propagated to the cylinder and affect the opening and closing timing of the injector in that cylinder, and that the injection amount and injection timing will vary.

The present invention provides a method for supplying high-pressure fuel into the common rail even if the high-pressure fuel passage around the common rail (for example, the injection pipe between the common rail and the injection valve, or the simple supply pipe between the high-pressure supply pump and the common rail) is broken. Hold The purpose of the present invention is to improve the reliability of the system by providing a mechanism for preventing the occurrence of pulsation of the fuel under pressure or a mechanism for preventing pulsation of the fuel under pressure.

For this reason, the first invention is provided with a mechanism for stopping the flow of fuel when the amount of fuel stagnation from the common rail to the injector exceeds a predetermined amount.

In the second invention, a mechanism is provided for preventing fuel from stagnation from the common rail to the high-pressure pump.

In addition, the No. 3 Kiyoshi has a mechanism to prevent the reverse of flutter from the injector to the common rail.

The fourth invention is a combination of the mechanisms of the first invention and the third invention. BRIEF DESCRIPTION OF THE FIGURES

Fig. 2 shows the overall composition of the first example, Fig. 2 shows a cross-sectional view of the injector, Fig. 3 shows a cross-sectional view of the check valve, Fig. 4 shows a cross-sectional view showing the operation of the check valve, and Fig. 5 Is a cross-sectional view of the safety device, FIG. 6 is a cross-sectional view showing the operation of the safety device, FIG. 7 is a characteristic diagram showing the relationship between the time t and the injection period c, and FIG. 8 is a diagram showing the relationship between the time t and the injection amount q. FIG. 9 is a characteristic diagram showing the relationship between the time t and the movement amount X of the ball 57, FIG. 10 is a cross-sectional view showing another example of the safety equipment S, and FIG. Sectional view of an embodiment in which the device and the check valve are combined, FIGS. 12 and 13 are modified examples of the embodiment of FIG. 11, FIG. 14 is a sectional view of the third embodiment, and FIG. FIG. 4 is an overall configuration diagram of the embodiment of FIG. 4;

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows the overall configuration of the fuel injection device for diesel engines of this embodiment, and Fig. 2 shows the injectors 36 provided for each combustion chamber of each engine cylinder.

In FIG. 2, the casing member 1 in the lower part of the city is composed of a body α 2, a chain 3 and a nozzle body 4, and the components 2, 3, 4 are integrated by a retaining nut 5. A valve body sliding hole 6 and a fuel reservoir 7 are formed in 4, and a nozzle hole 8 communicating with the fuel panning chamber 7 is formed at the end of the valve body sliding hole 6. The large diameter portion 10 of the slip needle 9 is slidably fitted. The large diameter portion 10 of the nozzle needle 9 has a speed adjustment portion 11 and a small diameter portion at the lower end. 12 and the valve body 13 are formed, and the seat X is opened and closed by the valve body 13, and the injection from the nozzle hole 8 is turned on / off.

Flange 14 and biston bin 15 are physically connected to the tip of the speed connector 11 of the nozzle needle 9, and biston 1 is attached to the end of the biston bin ί5. 6 are located. Nozzle needle 9 is urged in the closing direction by no. The piston 16 is slidably fitted in a cylinder 18 formed in the body lower 2, and a pressure is applied inside the cylinder 18 so that the tip of the biston 16 is exposed. A control room 19 is formed.

A plate valve 20 having an orifice is provided above the pressure control chamber 19, and a panel 21 for pressing the plate valve 20 is provided.

An upper casing member 23 having a three-way control valve 22 (solenoid valve) is in close contact with the body lower 2, that is, a cylindrical diasper 24 is extended to the body lower 2, The three-way valve body 25 is arranged in the internal hole of the body upper 24, and the refining nut 26 is inserted into the internal hole of the body-upper 24. An outer valve 27 is slidably fitted in the S-side valve body 25, and an inner valve 28 is disposed in an inner hole of the outer valve 27. When the coil 29 is demagnetized, the agitator valve 27 is at the lower position fi due to the force of the spring 30, and the high-pressure inverted passage 31 and the pressure control chamber 19 are rapidly moved through the oil passage 32. Passed. Moreover, _beta communicated via Autabarubu 2 7 is Ue勖, the pressure control chamber 1 9 and drain passage (low overwhelmed passage) 3 3 Togaabura passage 3 2 when the coil 2 9 is energized

A fuel supply passage 34 is formed in the lower casing member 1, one end of which is exposed to the surface of the casing member (body lower 2) 1, and the other end of which is quickly passed through the fuel pan chamber 7. The upper casing member 23 is quickly passed through the overturning passage 31 of the upper casing member 23. Further, an inlet 35 is screwed into the surface of the lower casing member (body α 2) 1 to supply fuel.ている Communicating with passages 3 4 ·

The high-pressure fuel in the pressure accumulation pipe (common rail) 38 described later is supplied to the fuel pan chamber 7 through the inlet 35 and the fuel supply passage 34, and the three-way control valve 22 Supplied to Further, the fuel in the drain passage 33 can be drained to the drain tank. Therefore, when high-pressure fuel is supplied to the pressure control chamber 19, the valve 16 receives the pressure and the force in the valve closing direction applied from the piston 16 to the nozzle needle 9 opens the valve due to the pressure in the fuel outlet chamber 7. The nozzle needle 9 closes the nozzle hole 8 with an upward force applied in the direction. In this state, the control valve 22 is controlled, the pressure control chamber 19 communicates with the drain passage 33 on the low pressure side, and the fuel in the pressure control chamber 19 flows out at a low pressure. Dollar 9 moves in the valve opening direction and fuel is injected. At this time, the fluid pressure slowly drops due to the action of the orifice of the brake valve 20 *

As shown in Fig. 1, such an injector 36 for each cylinder is It is connected to a high-pressure accumulator pipe 38 common to each cylinder via a firing pipe 37. The high-pressure supply pump 41 is connected to the pressure-accumulation pipe 38 via a supply pipe 39 and a tick valve 40. The high-pressure supply pump 41 is connected to the low-pressure fuel pump 4 from the fuel tank 42. The fuel sucked in through 3 is pressurized to a predetermined high pressure and controlled to a predetermined high pressure. That is, the cam 45 rotates in synchronism with the rotation of the engine 44, and the biston 47 in the cylinder 46 moves forward to pressurize the fuel from the low-pressure supply pump 43, thereby accumulating pressure. Supplied to 3-8. Also, the high-pressure supply pump 41 always controls the pressure of the pressure accumulating E pipe 38 to a predetermined pressure, that is, in order to control the amount of radiation to be pressure-fed to the pressure accumulating pipe 38, the pumping stroke of the piston 47. It is equipped with a solenoid valve 48 for controlling the discharge rate that closes at a predetermined time.

The electronic control unit (hereinafter referred to as ECU) 49 receives information on the number of surface turns and load from the cylinder discrimination sensor 50, crank angle sensor 51, and food load sensor 52, and receives these information. The ECU 43 outputs a control signal to the three-way control valve 22 so that the optimum injection timing and injection amount (injection rush) determined according to the determined engine side can be obtained.

Further, a pressure sensor 53 for detecting the pressure of the pressure accumulating pipe 38 is provided in the pressure accumulating pipe 38, and the ECU 49 transmits the signal of the sensor 53 to an optimal plant which is set in advance according to the load and the number of surface turns. The discharge amount is controlled so that In other words, a more precise pressure setting is performed by performing negative pressure control of the pressure. The discharge amount increases when the discharge timing TF of the high-pressure supply pump 41 is advanced,

In the middle of the injection pipe 37, a check valve 82 as a check member is provided. As shown in FIG. 3, the check valve 82 has a fuel passage 84, a valve body storage chamber 85, and a fuel passage 86 formed in a housing 83. A ball valve 87 is disposed in the valve body storage room 85, and a panel 89 for urging the ball valve 87 to the valve seat 88 is disposed. The fuel passage 84 is surrounded by an injection pipe 37a that is quickly connected to the injection valve 36, and The passage 86 is connected to an injection pipe 37 b communicating with the pressure accumulation pipe 38. Panels 89 of the check valve 82 have their set load set to be smaller than the common rail internal pressure minimum planting pressure P in and the ball valve pressure receiving area A 1 稹 (= P * in «A 1). The ball valve 87 is lifted by the internal pressure of 38, and the fuel passes when activated. The maximum load of the spring 89 is the maximum value of the accumulator piping internal pressure P 麵 ax and the value of the ball valve receiving pressure area A 1 (= P «ax ♦ A 1), so that even if P« a _X , the ball valve 87 does not block the upper fuel passage 84.

Then, when the fuel injection by the injector 36 ends and a reflected wave from the injector 36 falls to the rose pressure S pipe 38 in the injection pipe 37, the pole valve 87 is activated. reflected wave * Thus to be prevented from propagating inside the accumulator pipe 3 8 closed, interference of the cylinder easy to cause variation in the injection timing and injection quantity (pressure changes in the accumulator piping) can be prevented _β

As shown in FIG. 5, a safety device (flow limiter) 54 is provided between the pressure accumulation pipe 38 and the injection pipe 37.

The safety device S54 is provided in a housing 58 having a hollow cylindrical hole 60 in the 1¾ section and in the hollow cylindrical hole 60, and moves according to the amount of fuel supplied from the pressure accumulation pipe 38. The piston 59, the pressure accumulating pipe 3 8 of the piston 59, a press-fitted regulating member 62 that regulates the position of the piston 59, and a ball valve 57 that moves integrally with the piston 59 The ball valve 57 and the spring 61 are connected to and held by the spring 61 that urges the ball valve 57 toward the pressure accumulation pipe 38 and the ball valve 57 and the spring 61. And a retainer 63. A press-fit hole 64 is formed in the injection pipe 37 of the hollow cylindrical hole 60, and the diameter of the press-fit hole 64 is set smaller than the outer diameter of the ball valve 57 *. The restricting member 62 has orifices 55 a and 55, and the piston 59 has orifices 56.

Next, the operation of the safety device 54 is sharpened, 7 to 9 show time charts of the fuel injection period c, the fuel injection amount q, and the transfer amount X of the ball 57 in the safety device 54.

In the safety device S54, during normal (normal) operation, the fuel corresponding to the injection amount flows into the safety device 54 from the pressure accumulating E pipe 38 with the operation of the injector 22. The fuel enters the housing 58 from the orifices 55a and 55b of the regulating member 62, and moves the piston 59 according to the amount of the stagnation. With the movement of 59, the ball 57 also moves. The amount of movement of the ball 57 in the normal operating side is the amount of movement due to the flow of fuel (from the center of the ball 57 to the press-fit hole). It is set so as not to exceed the allowable value X corresponding to the separation. Therefore, the fuel flowing from the orifice 56 of the piston 59 passes through the periphery of the ball 57 and is pressed into the press-in hole. 6 and pass through the injection pipe 37, and is supplied from the injection pipe 37 to the injector 22.

On the other hand, for example, when a bug occurs during the program of the microcomputer of the ECU 49 or an abnormality occurs in the three-way control valve 22, the injection time of the injector 36 becomes longer, and When the movement amount X of 57 exceeds the allowable value X, the ball 57 is pressed into the press-fit hole 64 as shown in FIG. 4 and is permanently locked. Therefore, the safety device 54 completely stops the supply of fuel to the injector 36.

In addition, since the safety device 54 is disposed in the bridge between the pressure accumulation pipe 38 and the injection pipe 37, even if the injection pipe 37 is damaged, the safety device 54 allows the injector 36 to be operated. As in the case of failure, the supply of fuel to the injection pipe 37 is completely stopped.

Therefore, not only the failure of the injector 36 but also the damage of the injection pipe 37, the supply of fuel from the pressure accumulation pipe 38 to the isojector 36 must be stopped by the safety device 54. And safety is greatly improved. Next, another example of the safety device S5 will be sharpened using FIG. In the real旌例shown in FIG. 5, when the ball 5 7 is pressed into the press hole 6 4, although the Kyo耠of fuel to the permanent Nyi Nji _Λ Kuta 3 6 so as to俘止, this embodiment In the case where the amount of fuel flowing through the safety device S5 temporarily exceeds the allowable limit, the supply of fuel to the injector 36 is temporarily stopped, and when the amount of fuel continuously exceeds the allowable value. In order to stop the fuel supply permanently,

That is, as shown in FIG. 10, a seat part 1667 having a ball 157 seated in a housing 158 and a seat part it166 having a passage 169 are provided so as to be movable. At the same time, the sheet member 168 is urged by the return spring 165. The hole of the press-fit hole 164 is set to be larger than the outer diameter of the pole 157 and smaller than the outer diameter of the biston 159. The springs 161 and 165 are held by a spacer 172 having a fuel passage 166. According to this embodiment, the fuel spilling through the safety device gl54 is provided. If the value temporarily exceeds the allowable value, the piston 159 and the ball 157 move to sit on the sheet portion 167 of the seat member 168 and apply a force to the injector 36. Fuel supply is temporarily stopped. Then, when the amount of fuel flowing through the safety device S154 returns to within the allowable range from this condition II, the biston 159 and the ball 157 are also returned by the spring 161, and the accumulator piping The fuel from 38 will be supplied to the injector 36 again through the safety device 15 4.

Also, if an abnormality occurs in the injector 36, or if the injection pipe 37 is damaged and the fuel continuously flowing through the safety device 154 exceeds the allowable range, the piston 159 and the ball 157 moves and piston 159 is pressed into press-fit hole 164. Therefore, the movement of the ball 57 ® is completely restricted, and the supply of fuel to the injector 22 is stopped permanently * Next, an embodiment in which the check valve 82 of FIG. 1 and the safety device S5 are integrated will be described.

The rail between the common rail 38 and the injection pipe 37 is provided with a safety device S254 as shown in Fig. 11. The safety device 25 has an inlet port 256 and a hollow cylindrical hole 26. 0, a housing 258 having a press-fit hole 264 and an outlet 265 formed therein, a piston 259 slidably disposed in the hollow cylindrical hole 260, and a ball valve 257 And a panel 266 for urging the ball valve 257 toward the inlet 265. In the piston 255, an axial orifice 255 and a radial passageway 262 are formed, and at the same time, an annular sheet portion 263 closing the inlet port 256 is formed. It is formed.

Next, the operation of the safety device 254 will be described.

In the safety device g 2 54, during normal (normal) operation, the fuel according to the amount of radiation flows into the safety device 2 54 from the common rail 38 according to the operation of the injector 36. ,

This fuel flows into the housing 256 through the inlet 256, and moves the piston 259 against the urging force of the panel 266 according to the flow rate. Further, with the movement of the piston 255, the ball 257 also moves integrally. In the normal operation state I, the movement amount of the ball 257 exceeds the allowable distance corresponding to the separation from the center of the ball 257 to the press-fit hole 264 due to the flow of fuel. Not set. Therefore, the fuel flowing from the inlet 256 passes through the annular chamber 261, the 通路 -directional passageway 262, and the orifice 255, which are formed on the outer periphery of the annular sheet portion 263. Passes west of ball 255 and passes through outlet 265. Then, fuel is supplied from the outlet port 26 5 to the injector 36 through the injection pipe 37.

Also, when the amount of fuel flowing from the common rail 38 to the injector 36 is small, the ball 2 57 and the piston 25 9 are urged by the spring 26 6. It is pushed back by the force, and the annular sheet city 26 3 closes the poison inlet 25 6 Therefore, the fuel injection by the injector 36 ends in a holly, and the injection pipe 3 7 falls into the injector 36 and the accumulator pipe 3 When a reflected wave is generated on the common rail 38, the annular sheet part 263 of the piston 25 blocks the inlet 25, preventing the reflected wave from propagating inside the common rail 38. I have. As a result, it is possible to prevent interference between the cylinders (change in the pressure of the common rail 38 なる) that may cause a variation in the injection timing and the injection amount.

On the other hand, if, for example, a bug occurs in the microcomputer program of the ECU 49 or an abnormality of the three-way control valve 22 occurs, and the injection timing of the detector 36 becomes longer, the common rail 38 The amount of fuel entering the safety device 2 5 4 increases. Then, the movement amount of the ball 257 and the biston 259 exceeds the allowable range, and the ball 257 is pressed into the press-in hole 264 and is permanently locked. Therefore, the safety device 25 4 completely stops supplying fuel to the injector 36.

As described above, according to the present embodiment, the safety device IE254 can stop the fuel supply from the common rail 38 to the injector 36 in the event of an abnormality. At the end of fuel injection by 6, the annular sheet portion 2663 of the piston 255 closes the inlet 256, thereby preventing the reflected wave from propagating into the common rail 38. In addition, since these two different mechanisms are integrally formed in the safety device 254, the assemblability is greatly improved.

In the present embodiment, the safety device 254 is disposed between the common rail 38 and the injection pipe 37, but if it is in the fuel pipe from the common rail 38 to the injector 36. Any position may be used. Further, as shown in FIG. 12, the Yasuto of the biston 255 may be formed into a taper shape 267, and the sheet surface 68 of the II entrance 56 may be closed.

Next, another embodiment will be described with reference to FIGS.

In the embodiment shown in FIG. 13, the piston 25 9 has a directional passage 2 7 3 And a sheet part 274 is formed in the passage, and a check valve 270 for opening and closing the sheet part 274 is provided. The check valve 270 is composed of a plunger valve 272 and a spring 271 and opens when the fuel flows from the common rail 38 to the injector 36 side. The valve is configured to close against pressure transmission from the 6 side to the common rail 38, and has the same effect as the example shown in FIG. 11.

It will now be described real旌例in FIG 4 aimed only to prevent mutual interference of the I Nji _Λ Kuta _Λ

In the common rail 38, a check valve 362 is provided at a portion in contact with the injection pipe 37. That is, as shown in FIG. 14, the valve body storage chamber 365 is formed in the common rail 38 so as to communicate with the internal passage 38 a of the common rail 38. The plunger valve 3 6 6 allows the fuel to flow only from the common rail 38 to the guest pipe 37 and prevents the fuel from flowing from the injection pipe 37 to the common rail 38. And a spring 367, and a sheet material 3668 having a seat 369 on which the plunger valve 366 is attached. By screwing the fuel joint 370 in contact with the injection pipe 37 into the common rail 38, the seat member 368 is fixed, and the spring 366 is held.

The plunger valve 366 has a function of sucking the fuel pressure of the injection pipe 37 back to the common rail 38 by seating.

The spring 367 of the check valve 362 has its set load smaller than the product of the minimum common rail internal pressure P Plesin and the pressure receiving area A1 of the plunger valve 366 (= PainA1). The plunger valve 366 is lifted by the common rail internal pressure, and the fuel passes when it is activated. * Also, the maximum load of the spring 366 is determined by the maximum common rail internal pressure Pmax and the plunger. The product of the pressure receiving area A 1 of the valve 6 6 (-Ρ · 3 χ · A 1) It is set larger.

Then, when the fuel injection by the injector 36 ends and a reflected wave from the injector 36 falls to the common rail 38 falls in the injection pipe 37, the plunger valve 365, as shown in FIG. Closed reflected waves are prevented from propagating inside the common rail 38. This can prevent the cylinder cocoon from drying out (changing the pressure in the common rail), which causes variations in the injection timing and the amount of injection.

In addition, since the check valve 36 3 can be incorporated in the common rail 38 in advance, it is extremely easy to connect the injector 36 via the injection pipe 37 when the engine is mounted, and the workability is improved. Is greatly improved.

As described above, according to the present embodiment, in the common rail 38, the fuel supply from the common rail 38 to the injector 36 is allowed at the connection portion with the injection pipe 37, and the injector is connected to the injector 36. A check valve 36 (return member) is provided to regulate pressure transmission from 36 to the common rail 38, and reflection from the injection valve 36 to the common rail 38 along with fuel injection of the injection valve 36 The wave is regulated by the check valve 362. As a result, the interference between the cylinders due to the reflected wave, which causes the injection time and the injection amount to vary, is spread over the entire surface area of the internal combustion engine 閬. The check valve 36 2 can be installed in the common rail 38 in advance, greatly improving the workability when the engine is mounted.

In addition, in the implementation of FIG. 1 described above and FIG. 10, a safety device S was provided between the common rail 38 and the injection pipe 37, but a similar safety device was provided between the supply pipe 39 and the common rail 38. If provided in the capital, even if the simple pipe between the high-pressure supply pump 41 and the common rail 38 is broken, it is possible to prevent the high-pressure fuel from flowing out from the common rail 38.

In this case, the safety device may have check valves 4 2 1 and 4 2 3 shown in FIG. These check valves 4 2 1 and 4 2 3 are common To allow fuel to be supplied to the high-pressure bomb, and to restrict fuel flow from the common rail shelf to the high-pressure bomb.

On the other hand, if the fuel supply pipe 39 is damaged, the high-pressure fuel stored in the common rail 38 is passed through the fuel supply pipe 39 by the check valves 4 2 1 and 4 2 3. It is regulated and does not reach the high-pressure pump *, so that when the fuel supply pipe 39 is damaged, fuel can be prevented from flowing out from the common rail side.

Also, when the fuel supply pipe 39 is broken, the amount of fuel supplied from the descendant pressure pump 48 is supplied to the common rail 38, so that the fuel discharge timing is used to control the common rail pressure to a predetermined pressure. The TF (fuel discharge amount) is set to a small value (faster). Therefore, when the TF falls below the predetermined value T0, the ECU 49 considers that the fuel supply pipe 39 has been damaged and the high-pressure pump 4 8. Stop driving and fuel injection.

As described above, in this embodiment, the check valves 42 1 and 42 3 are provided at the end of the common rail 38 mm at the fuel supply pipe 39 to supply the fuel from the high pressure pump 48 to the common rail 38.耠 was allowed, and the fuel supply from the common rail 38 to the high-pressure pump 48 was regulated. As a result, even if the fuel supply pipe 39 is broken, the flow of fuel from the common rail 38 to the fuel supply pipe 39 is regulated by the check valves 4 2 1 and 4 2 3, and the outflow of high-pressure fuel can be prevented. Becomes

Next, among the two fuel supply systems from the high-pressure pump 48 to the common rail 38, a system devised to supply fuel to the remaining one system even if one system is damaged will be described.

As shown by the one-point line, the fuel supply pipe 39 is provided with pressure sensors 43, 43, and the fuel pressure in the fuel supply 39 by the pressure sensors 43, 43 is supplied to the ECU 49. It is being taken in. Then, when the fuel pressure in the fuel supply 39 by the pressure sensors 43, 43 becomes equal to or lower than a predetermined pressure value, the ECU 49 sets the fuel supply pipe having the reduced pressure. Assuming that the fuel supply has been damaged, the fuel supply to the damaged fuel supply pipe is stopped by controlling the discharge rate control magnetic valve, and the remaining fuel supply pipe is supplied with fuel.

As described above, in the present embodiment, the ECU 49 determines which fuel supply pipe has been damaged based on the signal from the pressure sensors 43 33 and 43 34, and determines one of the two fuel supply pipes. In the event that one of the diesel engines is damaged, fuel supply to the common rail 38 is controlled using the remaining fuel supply pipes. Even if one of them is damaged, the vehicle can be moved to a safe place. Industrial applicability

As described above in detail, according to the present invention, the outflow of high-pressure fuel when the high-pressure fuel passage around the common rail is broken, and the adverse effects of high-pressure fuel thats moving are prevented by a simple mechanism, and the reliability of the system is improved. ¾J β

Claims

The scope of the claims

1. Accumulator K tube for accumulating R pressure fuel,

A fuel pipe for leading high-pressure fuel from the accumulator pipe;

An injector which is provided for each cylinder, receives fuel from the fuel pipe, and injects fuel into the engine while being electrically controlled;

A safety device S is disposed between the pressure accumulating pipe and the fuel pipe, and when the amount of fuel supplied from the pressure accumulating pipe to the fuel pipe exceeds a predetermined value, a safety device S for stopping the flow of the fuel is also useful. Accumulation type fuel injection device *

2. A high-pressure fuel is supplied from a high-pressure pump through a fuel supply pipe, and a common rail for accumulating the fuel,

An injection valve provided for each cylinder of the internal combustion engine and connected through a branch pipe separated from the common rail;

A pressure-accumulation type fuel injection device S that controls opening and closing of the injection valve to inject fuel in the common rail to each cylinder of the internal combustion engine orchid so as to inject a fuel amount according to an operation state of the internal combustion engine. ,

A check valve is provided at the end of the common rail of the fuel supply pipe, which allows the supply of fuel from the high-pressure pump to the common rail and restricts the flow of fuel from the common rail to the high-pressure bomb. Characteristic accumulator type fuel injection device,

3. A common rail for accumulating high pressure fuel,

A fuel pipe for leading high-pressure fuel from the common rail;

An injector that is provided for each cylinder, receives fuel from the fuel pipe, and is electrically controlled to radiate fuel to the diesel engine 69, and is disposed in the common rail at a connection portion with the fuel pipe. A pressure-accumulating fuel, comprising: a non-return member that allows only supply of fuel from the common rail to the injector and restricts pressure propagation from the injector X to the common rail. Injection device.

4. A common rail for accumulating high-pressure fuel,

A fuel ffi tube that derives high pressure fuel from this common rail,

An injector that is provided for each cylinder and receives supply of fuel from the fuel pipe and injects fuel into the engine while being electrically controlled;

A safety device that is provided in the common rail or the fuel S pipe and shuts off the stagnation of the fuel when the amount of stagnation inside the fuel exceeds an allowable range;

A non-return mechanism provided in the safety device S, which allows only the supply of fuel from the common rail to the injector and restricts the propagation of pressure from the injector to the common rail. Pressure accumulating fuel injection device.

5. High pressure supply pump for pumping high pressure fuel,

A common rail for accumulating the fuel pumped from the high-pressure supply pump, a plurality of injectors for supplying the fuel accumulated on the common rail to the orchid,

A plurality of fuel piping for quick connect and each Yi Nji _Λ Kuta common rail, and a fuel supply耠管for connecting the high pressure Kyo辁pump and the common rail,

At least one of a joint between the common rail and the fuel K pipe and a joint between the common rail and the fuel supply pipe are provided to check that a sudden change in the pressure in the common rail has occurred. A pressure-accumulation type fuel injection device comprising: a valve mechanism for detecting and preventing this pressure fluctuation.

6. The accumulator type fuel injection device according to claim 5, wherein the valve mechanism has a check valve that allows only supply of fuel from the common rail to the injector.

7. The valve mechanism supplies fuel from the high pressure supply pump to the common rail. The accumulator type fuel injection device according to claim 5 or 6, further comprising a check valve that allows only supply.

8. The valve mechanism has a flow limiter that shuts off the communication between the common rail and the injector when the amount of fuel supplied from the common rail to the injector exceeds a predetermined level. An accumulator type fuel injection device according to any one of claims 5 to 7,